Jonathan Knutson, Forum News Service, Published December 16 2013
Weather expert offers cold forecast for months aheadGRAND FORKS – A chilly start to winter means it’s probably going to stay that way for the rest of the season, a Grand Forks weather expert is predicting.
“The traditional way of thinking about these cold-air beginnings to winter is that if it’s bitter cold to start the winter, it generally stays throughout the rest of the winter,” Leon Osborne, a professor of atmospheric sciences at the University of North Dakota, told a crowd at the annual Prairie Grains Conference in Grand Forks.
The rest of December will also see a number of “nickel and dime snowstorms” of no more than an inch each, he said. One or two significant storms are possible toward the end of the month, however, and area residents should monitor travel conditions, he said.
The rest of the winter in 2014 won’t get much warmer. But Osborne also had predictions for the seasons that farmers attending the conference really care about.
He said though late summer could turn hot and wet, the 2014 growing season should get off to a good start.
April might be cool, but temperatures will rise in May and June. Average temperatures in the three months, on balance, will be about average, he predicted.
Precipitation for the three months looks to be about normal, he said.
July through September, above-normal temperatures and near- or above-normal precipitation are expected, Osborne said, explaining that “normal” is based on a 30-year average for any given location.
The Upper Midwest’s 2013 weather was influenced by dual jet streams, “a rarity,” Osborne said. “Normally we just have one dominant jet stream. This year we actually had two.”
The jet stream is a current of fast-flowing air at high altitudes that plays an important role in weather formation.
The 2013 dual jet streams, “the smoking gun we’re looking at,” help explain why much of the region received heavy precipitation early in the summer and relatively little precipitation late in the summer, he said.
Though dual jet streams are rare, they have a tendency to happen in pairs. If they do occur again in 2014, the area’s weather could be affected for the second straight year, Osborne said.
The region’s 2013 weather also was influenced by the absence of both La Niña and El Niño, he said.
The two prominent weather phenomena involve tropical Pacific Ocean water and have global repercussions on weather and climate.
Now, however, El Niño is beginning to develop again, which could affect the region’s temperature and moisture in 2014, Osborne said.
“There’s still uncertainty on this. But the betting line is that we will see El Niño develop as we get into the latter part of next summer and that El Niño will continue to strengthen as we get into the next fall,” he said.
“Even if we start out a little bit cooler in the spring, we’ll make it up (with warmer temperatures) as we get into the August-September time period,” he said.
Development of El Niño conditions also could bring near-normal or even above-normal precipitation to a large portion of the central U.S. and into the Northern Plains, Osborne said.